I am going to deconstruct your question a little. I hope that's ok.
First, I don't think most audience members are reading "reviews." I put that in quotes because I think, as an example, reviews here (and even more so on social media) drive more business, especially for off-B, than "major" outlets.
Second, I don't think the marketplace of critical ideas I mentioned is limited to major outlets. As I have written before (and had folks challenge me on sometimes) I think we have more (written) critical conversation today than at any time in history.
Now, to your question, I think the sites that post collections of critic reviews (Playbill, BWW, formerly show-score) tee up the "major" ones. I link Playbill on Broadway Bounty Hunter, a show that notably did not seem to rattle all that many cages. That, to me, is a bigger problem than a bad review from the Times.
If I am missing your question, let me know, but I think this is my best take on the lay of the land.